books = ["Python编程从入门到实践", "围城", "小时候真傻，竟想着长大"]
book = "围城"

if book in books:
	print(f"书库中包含：{book}") 


newBook = "Git版本控制管理"
if newBook in books:
	print(f"书库中包含：{newBook}")
else:
	print(f"书库中不包含：{newBook}")


age = 20
if age < 4:
	print("免费")
elif age < 30:
	print("100元")
else:
	print("50元")